A Multicomponent Model of Radiation-induced Segregation for Commercial Stainless Steels

A radiation-induced segregation model of the Fe-Cr-Ni-Si-Mo system was developed to predict the change in grain boundary composition in commercial stainless steels under neutron irradiation. Parametric survey showed that there were strong influences on segregation behavior for the binding of Si to an interstitial and the jump frequency of Ni and Si via interstitial mechanisms. Careful setting of these parameters using effective point defect migration energies resulted in a good agreement between calculated results and measured data for SUS316 stainless steels irradiated to 74 dpa in light water reactor. Model calculation qualitatively reproduced the effects of dose rate, temperature, and bulk composition reported in the literature.